A machinists strike at the Lockheed Martin Aeronautics plant in Fort Worth, Texas, which manufactures the F-16 and the F-35 Joint Strike Fighter, has stretched into a seventh week, with no sign of an end. Demonstrations were also reported at the Naval Air Station in Patuxent River, Md., where union members are also employed, and at Lockheed Martin’s corporate headquarters in Bethesda, Md.

Machinists with the Fort Worth Local 776 of the International Association of Machinists and Aerospace Workers (IAM) stopped work April 23 after rejecting the company’s offer for a new three-year contract over changes to health insurance coverage and pension benefits for new hires. The union represents 3,600 of the company’s 14,000 workers at the Fort Worth complex.

Lockheed Martin issued a statement at the onset of the strike, describing the contract offer as “fair and equitable,” and including 3-percent annual wage increases and a $3,000 signing bonus. “We’re disappointed that the IAM members rejected the company’s last, best and final offer and voted to strike. Our operations will remain open and we will implement our contingency plan while focusing on meeting our commitments to our customers,” the company said.

Striking machinists in Fort Worth have been replaced with non-union workers, and the production line is “operating at near normal levels,” according to a Lockheed Martin informational website. The company reported “a normal F-35 flight tempo” at NAS Patuxent River and at Edwards Air Force Base, Calif., where F-35B/C and F-35A variants, respectively, are undergoing flight test.

The Fort Worth Star-Telegram reported June 6 that union officials had filed new complaints against the company, alleging unfair labor practices. The machinists union strike website stated: “There are no negotiations scheduled at this time.”